I need a plugin for when users register in my wordpress website, to be able to get a profile and be able to write articles, their articles go pending for review and then once I or an admin accepts their article, based on the amount specified for an article to get paid.

Like a portal where authors register and get paid per approved article.
Is there anything like that already on the market?

If you are searching on codecanyon for “marketplace”, you will find a couple of nice plugins which can do that with a bit of customization (basically any marketplace which supports digital items can be somehow configured to be an articles marketplace).